Service Brakes, Air:antilock:control Unit/module

NHTSA recall 79V077000 · announced March 29, 1979 · filed by Ford Motor Company · 65,000 units affected

The problem

CERTAIN AIR BRAKE ANTI-LOCK MODULATORS COULD MALFUNCTION DURING OPERATION OF THE ANTI-LOCK SYSTEM. A NYLON PISTON WITHIN THE MODULATOR AIR VALVE SYSTEM CAN SWELL FROM EXPOSURE TO SYSTEM CONTAMINANTS. CONTINUED EXPOSURE MAY CAUSE THE PISTON TO SWELL TO THE EXTENT THAT INTERFERENCE WITH THE CYLINDER WALL WILL RESULT, CAUSING MOMENTARY STICKING OR A PERMANENT JAM. THIS CAN RESULT IN TEMPORARY OR PERMANENT LOSS OF BRAKING FOR THE AFFECTED AXLE.

What to do

THE PISTONS IN THE VALVE PORTION OF THE MODULATORS WILL BE REPLACED WITH PISTONS THAT DO NOT SWELL WHEN EXPOSED TO AIR BRAKE SYSTEM CONTAMINANTS.

Notes

VEHICLE DESCRIPTION: HEAVY TRUCKS EQUIPPED WITH ANTI-LOCK AIR BRAKECONTROLLERS.SYSTEM: SERVICE BRAKES; CONTROL ASSEMBLY.

Vehicles covered by this recall

Source: National Highway Traffic Safety Administration public recall data. This page reports official records and is not legal, medical, or repair advice.